package com.atguigu.flink0624.chapter11;

import com.atguigu.flink0624.bean.WaterSensor;
import org.apache.flink.api.common.eventtime.WatermarkStrategy;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.Over;
import org.apache.flink.table.api.OverWindow;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;

import java.time.Duration;

import static org.apache.flink.table.api.Expressions.*;

/**
 * @Author lizhenchao@atguigu.cn
 * @Date 2021/11/19 10:26
 */
public class Flink13_Window_Over {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);
        
        DataStream<WaterSensor> waterSensorStream =
            env
                .fromElements(new WaterSensor("sensor_1", 1000L, 10),
                              new WaterSensor("sensor_1", 4000L, 20),
                              new WaterSensor("sensor_1", 4000L, 40),
                              new WaterSensor("sensor_1", 5000L, 50),
                              new WaterSensor("sensor_2", 3000L, 30),
                              new WaterSensor("sensor_2", 6000L, 60))
                .assignTimestampsAndWatermarks(
                    WatermarkStrategy
                        .<WaterSensor>forBoundedOutOfOrderness(Duration.ofSeconds(3))
                        .withTimestampAssigner((ws, ts) -> ws.getTs())
                );
        
        StreamTableEnvironment tenv = StreamTableEnvironment.create(env);
        
        Table table = tenv.fromDataStream(waterSensorStream, $("id"), $("ts").rowtime(), $("vc"));
        // 如果不是计算topN, 这个排序只能是时间的升序
        // sum(vc) over(partition by id order by ts rows between unbounded preceding and current row)
//                OverWindow w = Over.partitionBy($("id")).orderBy($("ts")).preceding(UNBOUNDED_ROW).as("w");
//        OverWindow w = Over.partitionBy($("id")).orderBy($("ts")).preceding(rowInterval(1L)).as("w");
//        OverWindow w = Over.partitionBy($("id")).orderBy($("ts")).preceding(UNBOUNDED_RANGE).as("w");
        OverWindow w = Over.partitionBy($("id")).orderBy($("ts")).preceding(lit(3).second()).as("w");
        table
            .window(w)
            .select($("id"), $("ts"), $("vc"), $("vc").sum().over($("w")).as("vc_sum"))
            .execute()
            .print();
        
    }
}
